1. Field of the Invention
This invention relates to cosmetic applicators, and is directed more particularly to applicators having an elongated roller to distribute a cosmetic product on the skin of the user.
2. Description of the Prior Art
Roller-type applicators for cosmetic products are well known in the art and have enjoyed wide commercial use, especially in the application to the skin of deodorants and antiperspirants. Convenient in use, they are also associated with high efficacy, due at least in part to their ability to deposit a concentrated dose of active material precisely where it will do the most good. Furthermore, environmental concern over the use of certain fluorocarbon propellants is causing renewed interest in non-aerosol means of dispensing and applying such products.
However certain types of product formulation lend themselves more readily to one kind of dispensing system than another. For example roller-type applicators function well and have been used with particular success for products having a uniform creamy or oily consistency, while pressurized aerosol dispensers have provided an effective way to spray products in the form of relatively unstable solid-liquid suspensions. Some of these suspension-type products, such as antiperspirants including certain aluminum or zirconium salts in a volatile silicone carrier, present special sealing problems in dispensing with an applicator comprising a roller in a socket. If the clearances are kept relatively close, as is customary, the ball is likely to stick or bind as the result of solids becoming trapped on the bearing surfaces. On the other hand if the clearances are opened up to accommodate such non-greasy suspension-type products, the sticking can be reduced, but leakage of the liquid carrier becomes a severe problem when, as often happens, the product is stored in any orientation other than upright.
It has also been found desirable in numerous applications to employ an elongated or oblong roller, in order to provide a wide contact area for applying deodorants, antiperspirants, and the like. However as can be appreciated, the problems of sticking and leakage described above for certain kinds of formulations become even more aggravated with a bigger roller.
Another difficulty with known roller-type cosmetic applicators having either a round or elongated ball turning in a socket is the tendency of the system to entrap and pull on body hair, a problem which affects a substantial portion of male users of roller-type deodorants and antiperspirants.